|
| |
|
|
A148281
|
|
Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 0), (0, 0, 1), (1, 1, -1)}
|
|
0
| |
|
|
1, 1, 2, 5, 12, 32, 92, 261, 772, 2372, 7238, 22596, 72206, 229686, 741392, 2431669, 7948084, 26247900, 87708782, 292258192, 981394918, 3325723982, 11242917210, 38238313052, 131010982918, 447908510662, 1538854377302, 5319179650346, 18350798477954, 63566944432482, 221330181884312, 769277947501077
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,3
|
|
|
LINKS
| A. Bostan and M. Kauers, 2008. Automatic Classification of Restricted Lattice Walks, ArXiv 0811.2899.
|
|
|
MATHEMATICA
| aux[i_Integer, j_Integer, k_Integer, n_Integer] := Which[Min[i, j, k, n] < 0 || Max[i, j, k] > n, 0, n == 0, KroneckerDelta[i, j, k, n], True, aux[i, j, k, n] = aux[-1 + i, -1 + j, 1 + k, -1 + n] + aux[i, j, -1 + k, -1 + n] + aux[1 + i, j, k, -1 + n] + aux[1 + i, 1 + j, k, -1 + n]]; Table[Sum[aux[i, j, k, n], {i, 0, n}, {j, 0, n}, {k, 0, n}], {n, 0, 10}]
|
|
|
CROSSREFS
| Sequence in context: A039809 A173611 A188287 * A148282 A148283 A002838
Adjacent sequences: A148278 A148279 A148280 * A148282 A148283 A148284
|
|
|
KEYWORD
| nonn,walk
|
|
|
AUTHOR
| Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008
|
| |
|
|
